Saw-mill dog



2 SheetsShet 1.

(No Model.)

' M. E. BENSON.

SAW MILL DOG.

0 H [l I IN VENTOI? WITNESSES.

A from/5Y8 2 Sheets-Sheet 2.

(No Model.)

M. E. BENSON.

SAW MILL DOG.

No. 436,203. Patented Sept. 9, 1890.

[I li k //v VENTOH mg z A TTORNE Y8 UNITED STATES PATENT OFFICE.

MARCUS E. BENSON, OF WEST PLAINS, MISSOURI.

SAW=M|LL DOG.

SPECIFICATION forming part of Letters Patent No. 436,203, datedSeptember 9, 1890.

Application filed March 24, 1390.

To all whom it may concern..-

Be it known that I, MARCUS E. BENSON, of West Plains, in the county ofHowell and State of Missouri, have invented a new and Improved Saw-MillDog, of which the following is a full, clear, and exact description.

The object of the invention is to provide a new and improved saw-milldog which is simple and durable in construction, very effective inoperation, and permits of freely moving the log up or down in case ofknots or crooks striking the collar of the saw, without, however,releasing the dog.

The invention consists of certain parts and details and combinations ofthe same, as will be hereinafter more fully described, and then pointedout in the claims.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

' cured a standard B, on which is held an adjustable frame 0, havingnear its upper and lower ends a slot 0, through which pass bolts D,screwing into the standards B and permitting a horizontal adjustment ofthe said frame O. Vhen the latter is in its innermost position, as shownin Fig. 3, its inner planed edge 0 fits into a vertical guideway B,formed on the standard B and serving to limit the inward motion of theframe 0. The bolts D are then in the right-hand end of the slots 0, asis plainly shown in Fig. 1.

In order to conveniently move the frame 0 horizontally on the bolts D inorder to adjust the dogs farther in or nearer to the side of the.log,levers E and E are provided, pivoted at E or E respectively, to thestandard B and preferably made of L shape, one end of each being pivotedto the frame 0, while the other ends of the two levers are pivotallyconnected with each other by the link E so that when one lever is movedthe other moves simultaneously, and the frame C is regularly Serial No.345,020- (No model.)

Fig. 3, the two guideways O and 0 being engaged by a vertical slidingcarriage F, carrying the upper dog G, provided with the usual point- G,adapted to engage the log under treatment.

On the upper part of the carriage F is mounted to turn in suitablebearings the transversely-extending shaft H, on which is secured agear-wheel I, in mesh with a rack J, fitted to slide vertically on theinner face of the projection 0 The rack J is supported at its lower endon a vertically-extendingcoiled springK, extending through a recess 0,formed in the projection C the upper end of the spring being fastened tothe top of the frame 0. (See Fig. 1.) On the lower end of the rack J issecured a slide or carriage L, fitted to slide on the guideways O and Osimilarly to the carriage F, the said slide L supporting the lower dogN, provided with the usual upwardly-extending point N, adapted to engagethe log from the under side, as is plainly shown in Fig. 1. v Thegear-wheel I, previously mentioned, is adapted to be engaged by a pawl 0held on two bolts P, extending transversely through slots Q in the leverQ, f ulcrumedjloosely on the shaft H. The bolts P also support onthe'opposite face of the lever Q an arm R, having a segmental edge R,adapted to be pressed in contact by a spring R with the segmental edgeF, formed on the carriage F, concentric with the shaft II on which thelever Q'is fulcrumed. The said arm R is also adapted to be engaged bythe beveled end of a plate F secured to the top of the carriage F andhaving its point passing onto the segmental edge F of the carriage F, asis plainly shown in Fig. 2.

When the lever Q is thrown into a vertical position, the arm B travelsup. the beveled end of the plate F so that the said arm slides outwardand carries along the pawl O, which latter is thus disengaged from thegearwheel I.

When the lever Q is moved downward, so that the arm R passes off thebeveled end of the plate F then the spring R pressing on the said arm R,causes the latter to slide inward, thereby moving the pawl O in the samedirection-that is, in engagement with two teeth of the gear-wheel I.

On the shaft H and at its front end is fulcrumed loosely a camS,supported on an arm S, fastened to the lever Q, so that the said cam Sturns with the swinging of the lever Q, as hereinafter more fullydescribed.

The cam S is adapted to engage with its cam-edge the releasing-arm T,pivoted at T to the dog G, and adapted to engage with its outer end Tthe log under treatment next to the point G, so as to withdraw thelatter whenever desired, and as hereinafter more fully described.

The operation is as follows: The operator first moves the lever Q into avertical position, so as to disengage the pawl 0 from the gear-wheel I,as previously described, to enable the operator to move the carriage Finto the uppermost position, the gear-wheel I then traveling looselyover the rack J. The operator then throws the lever Q into ahorizontalposition, so that the pawl O engages the gearwheel I, as previouslydescribed, and as the entire weight of the said carriage and itscontents now hangs on the rack J, the latter slides downward until thelower dog N is below the top of the head-block A, thereby permitting thelog to be rolled onto the headblock in the usual manner until it restsagainst the outside of the projection C When the log has been rolled onthe head-block, the operator raises the lever Q into a perpendicularposition, so as to disengage the pawl 0 from the gear-wheel I, therebyreleasing the rack J from the Weight of the carriage F, so that the saidrack slides upward by the action of the spring K and movesthe lower dogN, with its point N, into the log from underneath. At the same time theoperator lets the carriage F slide downward by its own weight, so thatthe point G of the upper dog G engages the log from the top. Theoperator then swings the lever Q downward into about the position shownin Fig. 1, so that the gear-wheel I is turned in the direction of thearrow at, thereby exerting the upward pressure against the rack J, atthe same time causing the downward sliding of the carriage F, wherebythe points G and N of both dogs G and N are moved toward each other andpressed into the log, so that the latter is securely held in place.

It will be seen that as the lower dog N is supported on the rack whichsupports the carriage carrying the upper dog and is yield in gly mountedon the spring K, it follows that in case the saw strikes knots or crooksthe log can yield, at the same time being securely held in place by thetwo dogs.

It will further be seen that when the operator desires to release thepoints G and N of the dogs G and N from the log, the operator moves thelever Q upward, so that the gear-wheel I travels in the inversedirection of the arrow at and moves the rack J downward and the carriageF upward, thereby withdrawing the points of the two dogs from the log.

When the operator desires to grasp the cant or squared log to be sawedup to the last board, he moves the handle E of the lever E down, so thatthe frame 0 slides to the right until the points of the dogs G and Nproject only three-quarters of an inch into the timber. The operation of(logging the cant is then the same as for the log.

When the lever Q is moved upward to disengage the points G and N of thetwo dogs G and N from the log, the cam S presses on the releasing-arm T,so that the end T of the latter engages the rim of the log alongside thepoint G, so that the latter is easily withdrawn.

Having thus fully described my invention, I claim as new and desire tosecure by Letters Patent- 1. The combination, withthe frame, of avertically-reciprocatin g rack-bar thereon carrying the lower dog andhaving a free upward movement beyond that required to bring the saidlower dog into engagement with the log, with a carriage mounted on theframe and having a gear engaging the rack to raise and lower it, andmeans for locking the gear to the rack, whereby if an obstruction on adogged log strikes the saw-collar and causes the log to rise, the rackwith the two dogs will yield upwardly, substantially as set forth.

2. In a saw-mill dog, the combination, with a frame and avertically-sliding spring-sup ported rack supporting the lower saw-milldog, of a gear-wheel in mesh with the said rack and a carriage mountedon the frame and carrying said gear-wheel and supporting the uppermostdog, substantially as shown and described.

3. In a saw-mill dog, the combination, with a frame and avertically-sliding spring-supported rack supporting the lower saw-milldog, of a gear-wheel in mesh with the said rack, a carriage mounted onthe frame and carrying said gear-wheel and supporting the upper dog, anda pawl and lever for turning IIG the said gear wheel, substantially asshown I and described.

4. In a saw-mill dog, the combination, with a frame and avertically-sliding spring supported rack supporting the lower saw-milldog, of a gear-wheel in mesh with the said rack, a carriage mounted onthe frame and carrying said gear-wheel and supporting the upper dog, apawl and lever for turning the said gear-wheel, and means, substantiallyas described, for disengaging the said pawl from the said gear-wheel,substantially as shown and described.

5. In a saw-mill dog, the combination, with a yieldinglymounted racksupporting the lower saw-mill dog, of a gear-wheel in mesh with the saidrack, a carriage carrying said gear-wheel and supporting the upper dog,a pawl and lever for turning the said gear-wheel, means, substantiallyas described, for disen gaging the said pawl from the said gear-wheel,and a releasing-arm held alongside the uppermost dog and adapted to beactuated by the said lever, substantially as shown and described.

6. In a saw-mill dog, the combination,with a standard and a verticalframe adjustable horizontally thereon, of a vertically-sliding carriagemounted on and carried by the frame, a dog secured thereto, a gear-wheelmounted on the said carriage and provided with an operating-lever havinga pawl engaging said gear, a vertically-sliding rack on said frame andengaged by said gear, and a dog on the lower end of the rack,substantially as set forth.

7. The combination, with the frame, a vertically-sliding rack thereonprovided with a dog, and a spring secured at its upper end to 0 theframe and at its lower end to a projecting part at thelower end of therack to support the rack, of a vertically-slidin g carriage on the frameprovided with a dog and means for locking the said carriage to the rackto yield therewith, substantially as set forth.

8. The combination,with the frame having vertical guideways, a rackhaving a free upand-down movement only in the frame be tween saidguideways and carrying the lower dog, of an upper carriage mounted toslide vertically on-said guideways in either direction and held therebyfrom lateral movement on said frame, an upper dog carried by saidcarriage, agear also mounted on the carriage and meshing into the rack,and an operatinglever provided with a pawl engaging the said gear,whereby the rack and both dogs will be permitted to simultaneously yieldvertically, substantially as set forth.

9. In a saw-mill dog, the combination,with a carriage and a dog securedthereon, of a gear-wheel mounted to turn in the said carriage, a leverfulcrumed on the shaft of the said gear-wheel and carrying a cam, and areleasing-arm pivoted on the said dog and extending in line with thelatter, substantially as shown and described.

MARCUS E. BENSON.

Witnesses: VoLNEY D. GoRHAM, J. B. THORNTON.

